An electrical generator used in the field of electrical power generation includes a stator winding having a large number of conductor or stator bars that are pressed into slots in a base body, in particular, a laminated stator core or a rotor body. Such an electrical generator represents a very expensive and long-term investment. Its failure not only endangers the power equipment itself but may also result in very severe service reduction due to the down time associated with repair. To avoid such a condition, a diagnostic system may be used for early identification of defects or deterioration in operation. The diagnostic system may further allow a higher utilization level, making the power equipment more financially viable.
For example, in an electrical generator, hydrogen or air may typically be used as a cooling medium for parts of the generator such as the stator core and the end winding region, and additionally may be used to cool the stator coils and the rotor. Ventilation for proper cooling of the generator components is built into the design and generally may be essential to the continued safe operation of the electrical generator. It has been observed that many problems resulting in generator failure and costly power plant outages may be traced to inadequate ventilation, i.e., ventilation not being provided in accordance with design conditions. In particular, unintended flow modification of the cooling flow may be caused by parts that come loose during generator operation, mislocated baffles, leaking seal strips, and dislodged and migrating insulation filler strips, which may result in overheating of parts and insulation failure.
Existing monitoring systems include monitoring temperature as an indication of a condition of select locations within an electrical generator. However, such temperature monitoring may not provide information on the cause of temperature variations, such as causes relating to unintended flow modification of ventilation flow through the generator.